Fuel pump



Dec. 16, 41941.

A. M. BABITCH ETAL FUEL PUMP Filed July 3, 1939 2 Sheets-Sheet 1 qa'Gttornegs Dec. 16, 1941. A. M. BABlTcH E-rAL FUEL PUMP Filled July 3,1959 2 Sheets-Sheet 2 Patented Dec. 16, 1941 2,266,291 FUEL PUMP AbrahamM.

Flint, Mich., poration, Detroit, ware Babitch and Gordon W. Harry,assignors to General Motors Cor- Mich., a corporation of Dela-Application July 3, 1939, Serial No. 282,707

4 Claims.

This invention relates to pumps and has been designed to improve thepumps which are used to supply fuel for internal combustion engines.

An object of the invention is to provide an improved operatingmechanism.

Another object resides in an improved form of pulsator.

Other objects and advantages will be understood from the descriptionwhich follows.

In the drawings:

Figure 1 is a vertical section through one embodiment.

Figure 2 is a vertical section at right angles to that shown by Figurel.

Figure 3 is a top plan view partly broken away and in section.

Figure 4 is a, vertical section through the upper part of the modifiedform.

Figure 5 is a vertical section through the upper part of anothermodification.

Figure 6 is `a horizontal section through the modification shown inFigure 5.

Figure 7 is a vertical section of a modified form of operatingmechanism.

In the form of invention shown by Figures 1 to 3, numeral II is used todesignate a housing for the operating mechanism. `Numeral I3 is the bodymember of the pump and I5 is a cap. Bolts |1 secure these partstogether. The main diaphragm marked I9 is clamped between lthe housingII and the body I3. A second diaphragm 2| constituting a part of apulsator is clamped between body I3 and cap I5. Housing is closed by acover 23 secured by screws 25.

The body I3 at its top has a circular ledge 21 forming a space 29beneath diaphragm 2|. The body I3 has a lower circular ledge 3| forminga space 33 above the diaphragm I9. As shown by Figure 3 the body I3beneath the space 29 is formed into two arcuate chambers 35 and 31 whichare open to space -29. The two chambers 35 and 31 are separated by atransverse partition. This partition includes a circular dome 39 closedat its top and open to the space 33, an inlet passage 45 extendingsomewhat radially and a similar and slightly offset outlet passage 41.

A flange 53 seats against the body over the inlet passage 45 and holdsin position an inlet valve designated by numeral 55. This valve controlsa passage of fuel from a source of supply to the fuel pumpclramber 3 3.A second-ange 51 is secured to the body over the outlet passage 41. Ithouses an outlet valve 59. Just beyond valve 59, flange 51 is formedwith a passage 6| registering with a passage 63 in the body, passageopening is a shaft 1| having a projecting driving end 13.

At the other end of this shaft and Within the housing is an eccentricpin 15. Rotatable on pin 15 isy the eye 11 of a link 19. A second link8| is rotatably associated with link 19 by a connecting pin 83. Links 19and 8| have arms 85 and 81 respectively and a coil spring 89 isconnected to these arms. In pulling the arms together the spring bringsinto contact faces 9| and 93 on the links and dov so before the linksreach alignment. A retaining links 95 is pivoted to the housing at 91and its other end is pivoted to link 8| by pin 99. Pin 99 is alsoconnected to the lower forked end of a stem |0I. The stem has a neck |03and a head |05. The head and the neck are projected through arectangular aperture of a plate |01. Thereafter the stem |0| is rotatedabout its axis through 90 degrees to lock the stem and plate |01 fromseparation. This construction will be understood by comparing Figure 1and Figure 2. Above and below the diaphragm are reinforcing plates |09.The two plates, the diaphragm, and the plate |01 are secured together byfastening means The pump may be located in a'ny position where drivingmeans is available for rotating shaft 1|. The eccentric pin operatesthrough the instrumentality of links 19 and 8| and the stem |0I toreciprocate the diaphragm. Fuel is drawn into the pump chamber throughvalve in response to the suction stroke of the pump and it is forciblyejected through valve 59 by the discharge stroke. Uniform discharge ismade possible by the pulsator, the pulsator including chambers 35, 31and 29 together with the diaphragm 2| backed by the` air cushion betweenthe diaphragm and the cap I5. Spring 89 biases the linkage to thatposition where faces 9| and 93 are in contact with the result that aslong as this contact is made, full strokes both of suction and dischargeoccur. The discharge stroke may be resisted by built up pressure at thepump outlet due to the closure valve in the carburetor. When this outletpressure is sufficient to overcome spring 89, the spring yields and acollapse of Ilinks 19 and 8| occurs. It will be observed that since thespring is connected only to the links and has no contact 63 55 with@fixed abutment its force is applied wholly to the diaphragm and it oiersno resistance to the suction stroke merely opposing resistance to thedischarge stroke to the extent of the built up pressure at the pumpoutlet valve. The force required to operate the pump is thereforereduced to a minimum owing to the noating support of the spring.

Figure 4 shows.a modification in which the body I3 has inlet and outletports substantially as before. The body has a depressed region |02, thespace around this region being a part of the pump chamber. Above thebody is a member |04 having an intermediate partition |06. A diaphragm|08 is preferably clamped between the circular margins of the bodymember and member |04. In advance of the outlet valve the body is formedwith a passage H2 communicating with a passage ||4 in member |04 leadingto the space between the diaphragm |08 and the partition |06, thisspa-ce serving as a pulsator for the outlet valve. To provide a pulsatorfor the inlet valve there is a second diaphragm ||6 located between thetop of member |04 and a cap ||8. 'I'he space between the partition |06and the diaphragm ||6 is in communication by suitable passages in themember |04 and the body member with that side of the inlet valve remotefrom the pump chamber. struction a pulsator effect is provided for boththe inlet and discharge of fuel.

The modification by which a double pulsator may be provided with but asingle pulsator diaphragm is shown in Figures and 6. In these gures abody 20| and cap 203 clamp between them a diaphragm 205. The body andcap have transverse partitions 201 and 209 registering with each otherwhereby two chambers 2|| and 2| 3 are formed. The chamber 2|3communicates by means of passages 2|5 and 2I1 in the body and the valvecarried ange 2|9 with the region beyond the outlet valve. Chamber 2|| issimilarly associated with the space on the side of the inlet valveremote from the pump chamber. Suitable means 2 I0 secure to them the capand the body.

For some purposes the operating arrangement shown in Figure 7 may beused. In this form a stem 30| is connected to a diaphragm, not shown,and corresponds with the stem |0| of Figure 1. Links 305 and 301connected together at 309 are terminally connected at 3|| to the stem30| and to an eccentric 3|3 on a rotary shaft 3|4. A guide link 3|5 isconnected to pin 3|| and to By this conspring 323.

a pin 3|'| carried by the housing. Link 301 has a specially formedsurface 3|9 to engage a pin 32| in link 305 and thereby preventsalignment of the links. A spring 323 is hooked to pin 30B and to a plug320 adjustably held within a tubular member 325 threaded into thehousing. A nut 326 threaded on the plug and engaging the end of tubularmember 325 provides adjustment for the spring. In this form of theinvention the surface 3|9 of link 301 normally engages the pin 32| oflink 305 under the influence of the This relation of links 305 and 301prevails at all times except when the outlet pressure of the pumpovercomes the tension of the spring 323 at which times during thedischarge movement of the eccentric the linkage collapses.

We claim:

1. In a pump, a movable pumping member having a stem, a rotary drivingmember having a part movable therewith in response to rotation of saidmember to extreme positions substantially in the axis of said stem,links jointed together and to said stem and part, a floating springconnected to said links, cooperating members on said links adapted toengage and to prevent link alignment under the inuence of said spring.

2. In a pump, a movable pumping member having a stem, a driving memberhaving a part adapted to move toward and away from said stem, linksjointed together and to said stem and part, a oating spring' connectedto said links, cooperating members on said links adapted to engage andto prevent link alignment under the inuence of said spring, said pumpincluding a housing and a guiding link terminally pivoted to saidhousing and to said stem.

3. 'Ihe invention dened by claim 1, said jointed links having arms andsaid spring terminally attached to said arms.

4. In a pump, a movable pumping member having a stem, a driving shafthaving an eccentric pin, said pin adapted to assume extreme positionssubstantially in the axis of said stem in response to rotation of saidshaft, links jointed together at their adjacent ends and terminallypivoted to said stem and pin, a floating spring connected to said links,and cooperating members on said links adapted to engage and to preventlink alignment under the influence of said spring.

ABRAHAM M. BABITCH. GORDON W. HARRY.

